Turn on the TV, open a major newspaper or scroll through Twitter, and you’ll likely see Donald Trump referred to as a populist. Whether Trump is actually a populist is a matter for debate. The most important connection between Trump and other populists – such as Jean-Marie Le Pen in France – is the anti-establishment nature of Trump’s rhetoric. Recently in the Monkey Cage, Pippa Norris compared him to radical right-wing populists in Europe and argued that this style of populism is one of cultural backlash. If we look beyond Europe, however, we see more to the story.

By looking at the Latin American experience with populism, we see that the rise of right-wing populism is more than just cultural backlash. Populists in Latin America tend to be far more inclusive than their counterparts in Europe. For instance, Hugo Chávez or Evo Morales built highly inclusive bases that cut across class, ethnic and religious lines. Populists in Europe, on the other hand, tend to be far more exclusive, drawing support from people who hold hyper-nationalist and anti-immigrant attitudes.

Latin American populists are also far more successful at the ballot box than their European counterparts. Selecting 136 parties in 26 countries in the Americas and Western Europe, Kirk Hawkins and Bruno Castanho Silva scored speeches and manifestos on how much they employ populist language. They then averaged this score across parties and weighted it by the average electoral results. The resulting score measures how prevalent populism is in a given party system.

Using their data, I created the graph below, showing a weighted score of how populist parties are by their level of electoral success. Here we see that even the most successful populist parties in Europe aren’t as successful as those in Latin America.

How can Latin American and European populism help us understand today’s GOP and Trump?

So why are Latin American populists more inclusive and successful than those in Europe? Perhaps an answer to this lies in how strong the party systems are, which political scientists call party system institutionalization. By that we mean whether and how well a country’s political parties are organized, linked to groups within society, and professionally staffed, as well as whether their platforms or ideologies are coherent, and whether the party’s legislative representatives vote along party lines.

Using a new score of party system institutionalization from the Varieties of Democracy Project, I mapped the relationship between the institutionalization of party systems and the electoral success of populist parties.

Prevalence of populism and party system institutionalizationData: Hawkins and Silva 2016, Varieties of Democracy; Figure: Darin Self

Here’s what you can immediately see: Latin America has weaker party systems – and its populists are more likely to win elections. That’s because other parties regularly fail their voters, unable to deliver what societies expect from their governments.

In Europe, by contrast, party systems are stronger – and populist parties are less appealing to voters. That’s in part because European systems’ parties address concerns held by broad portions of society – and deliver the policies that they demand. As a result, populists can’t compete directly with those established parties. Instead, they appeal to a small niche with a brand of populism that peddles exclusivity and fear.

U.S. political parties are realigning

What does this mean for the United States? Here, too, a slice of society would vote for a radical-right party. But given the strength of the U.S. two-party system, such a party wouldn’t get far in national elections; its base would be too narrow. The rise of Trump within the GOP is not the transformation of the GOP into a radical-right party.

Rather, we are witnessing what Gary Miller and Norman Schofield described in 2008 as a realigning of the two U.S. political parties along the social and economic ideological spectrum. We are watching as social conservatives push against economic conservatives who are increasingly more socially liberal. No longer, it seems, can these two groups share the same Republican Party. Social conservatives are rejecting the views of the economic conservatives by voting for Trump.

In many other democracies parties, not voters, select candidates. In these other democracies, we do not see more radical candidates, like Trump, rise to prominent positions within the party because members of the party fall in line behind party leaders.

Compare this to the current Republican Party, in which all three Republican candidates now say they won’t necessarily support “the eventual nominee.” Other prominent Republicans, such as Sen. Lindsey O. Graham of South Carolina and Mitt Romney, are debating the same question. Still other conservative thinkers, such as New York Times columnist David Brooks, are debating the need for a conservative third-party candidate as a way to save face for the Republican Party.

The U.S. two-party system has no room for a niche radical-right party. And the Republican Party’s candidate selection rules make the GOP — the actual party itself — weak. That weakness unlocked the door for Trump. Now the GOP must watch a potentially uncontrollable candidate define what their party stands for, rather than doing it for themselves.

It doesn’t matter if Trump is a populist, fascist or some other ist or not. What is clear is that he is not beholden to anybody or any party – especially the Republican Party.

Darin Self is a Ph.D. student in political science in the department of government at Cornell University. Find him on Twitter @darinself.